Stern wants to stabilise the amount of carbon dioxide (measured in parts per million) at 550. In pre-industrial times, it was 280, and today, this figure is at 420.

What's horrifying is that the report assumes that if we spend 1% of global GDP now, it will only address the global warming that will occur from 2050 until the next century. All the carbon that will warm the planet until 2050 is already in the atmosphere, or will be emitted even with drastic cutbacks from now until then.